The Romance of Modern Chemistry

VALUABLE SUBSTANCES besides colouring matters. Even Punch at one time felt moved to wonder at the host of things that have their origin in coal tar, and delivered himself of the following lines:— “ There’s hardly a thing that a man can name Of use or beauty in life’s small game But you can extract in alembic or jar From the 'physical basis’ of black coal tar. Oil and ointment, and wax and wine, And the lovely colours called aniline; You can make anything from a salve to a star, If you only know how, from black coal tar.” “Anything from a salve to a star” is rather a big order, but the variety of purposes to which the derivatives of coal tar are applied is certainly very remarkable. In photographic developers, in the colour of microscopic sections, in patent fuel, in the colour of our butter, in artificial perfumes, in the surgeon’s antiseptics, in the latest shade of tie, and in the explosive lyddite, we may detect the trail of the tar. Some readers may be interested to know that among the drugs to which the study of benzene and its deriva- tives have led are the well-known antipyrine and phena- cetine, as well as a host of others which would not be so familiar. Whoever wants a local anæsthetic, a hypnotic, or an antiseptic can have his requirements met by some- thing which has been derived from coal tar. As a last example of the unexpected things that have cropped up during the study of coal tar products we may take saccharine. This substance is prepared from the hydrocarbon toluene, and therefore indirectly from coal tar. Its most remarkable property is its sweetening power, 288